RFC-0153 Emoji ID secret key should also be stored in stage 1b

[stringhandler]

The emoji id for a wallet should not change when a restore is done. If the seed words are removed, then the restored wallet will have a different emoji id.

I suggest storing the secret key for the emoji id in stage 1b, or at least mentioning that it should be explicitly removed

[CjS77]

Correct. To avoid leaking all future funds, the trade-off is that you import the old UTXOs into a new wallet. You're not really restoring the wallet per sė. We should update the text to make this clear.